地震と雪の荷重組合せを考慮した動的解析に基づく鋼構造大スパン建物の被害確率評価

摘要

大スパン鋼構造建物を対象として，地震と雪の荷重組合せを検討 し，建築基準法とは異なる荷重組合せの必要性を考察した。異なる 積雪荷重と地震動レベルにおける建物被害を時刻歴応答解析により 検討し，構成部材に作用する最大応力度から建物被害を推定し，対数正規分布で各荷重と被害率の関係を表すことで地震と雪の組合せ によるフラジリティ曲面を示した。地震動と雪のハザード曲面とフ ラジリティ曲面から，建築基準法の規定以外の組合せの検討の必要 性を指摘した。%Recently, disasters due to concomitant hazards of earthquake and snow have been increasing in Japan. When engineers verify the structural safety of buildings in a heavy-snow region by means of structural calculation, a coefficient value of 0.35 is used for snow weight under load combination with earthquake with reference to Building Standard Law of Japan. This paper investigates the necessity of load combination of moderate earthquake and moderate snow. The fragility surface of a large span steel frame under seismic excitation and snow load is developed based on dynamic analysis. Two kinds of damage-related responses, the maximum stress of members and the maximum response acceleration of ceilings are examined. With respect to the maximum stress, the evaluated fragility surface and joint hazard surface of earthquake and snow suggest that additional consideration is required for load combination of moderate earthquake and moderate snow.